Read the sheet in the order it is installed
Most waterproof gobo projector sheets list ten numbers and leave out the three that decide the result. Work from the wall backwards — image size, throw distance, ambient light — and treat everything else as supporting detail. The numbers that matter are the ones you can verify on site with a tape measure and a lux meter.
Output numbers, ranked by how much they lie
Wattage tells you the running cost, not the result. Two waterproof gobo projector models at the same wattage can differ by 30% at the wall because of lens efficiency and LED binning. What you actually care about is contrast: the image needs to be meaningfully brighter than the surface it lands on, and that is a lux comparison, not a lumen one.
| Figure | What it measures | How much to trust it |
|---|---|---|
| Lumens | Total light leaving the lamp | Rough sorting tool — ignores lens and gobo losses |
| Lux at the wall | Light arriving on the surface | The number that matters, rarely quoted |
| Watts | Power drawn from the supply | Tells you running cost, not brightness |
The two numbers that must be quoted together
Check whether the quoted throw is to a white wall in a dark room, because that is where the number comes from. On a waterproof gobo projector intended for an entrance canopy, the realistic working distance is usually shorter than the maximum on the sheet, since contrast — not reach — is what fails first.
| Throw | Typical image width | Practical note |
|---|---|---|
| Short, around 5 m | 0.5 – 1.5 m | Bright and easy — most indoor work |
| Mid, around 35 m | 1.5 – 3 m | Where lens quality starts to matter |
| Long, beyond 35 m | 3 m and up | Contrast fails before reach does |
The optical spec most sheets leave out
Two numbers govern the image: gobo image area and the resolution the lens can carry. Glass gobos can be engraved far finer than any waterproof gobo projector lens in this class will resolve, so the practical limit is optical. That is worth knowing before you pay for engraving detail nobody will see from 10 m away.
The compliance block
The electrical block is boring and expensive to get wrong. Confirm the input voltage range matches your supply, check whether the waterproof gobo projector ships with a local plug, and look for CE, RoHS and FCC marks if the install is commercial. A unit that is electrically fine but uncertified will not pass a site inspection in most markets.
Questions worth asking the supplier
The most revealing question is about failure. Ask what the most common warranty claim on this waterproof gobo projector is and how it is resolved. A supplier who answers honestly is worth more than one with a slightly better spec sheet.
